The 1965 Irish general election to the 18th Dáil was held on Wednesday, 7 April, following the dissolution of the 17th Dáil on 18 March by President Éamon de Valera on the request of Taoiseach Seán Lemass. The general election took place in 38 Dáil constituencies throughout Ireland for 144 seats in Dáil Éireann, the house of representatives of the Oireachtas. The governing Fianna Fáil saw a slight increase, though did not obtain a majority.

The Taoiseach is the head of government or prime minister of Ireland. The office is appointed by the President of Ireland upon the nomination of Dáil Éireann and the office-holder must retain the support of a majority in the Dáil to remain in office.